Necrotizing Enterocolitis (NEC)

Necrotizing enterocolitis (NEC) is a serious illness and is one of the most common GI emergencies in newborns and youth. It happens when the lining (mucosa) of the intestine gets inflamed. The inflammation damages and sometimes kills the tissue in the intestine.

Any newborn can get NEC, but it is most common in premature babies. It is also found in a small number of babies in neonatal intensive care units. NEC is more common in babies weighing less than 3 pounds, 4 ounces (1,500 grams).

What causes necrotizing enterocolitis?

Doctors do not know what causes NEC. It may happen if not enough blood and oxygen reaches the intestinal tissues. Then when food moves into the weakened area, bacteria from the food can damage those tender tissues. This can cause the tissues to become damaged and die. When this happens, a hole forms in the intestine. This can lead to severe infection in the baby’s belly.

Who is at risk for necrotizing enterocolitis?

  • The bodies of premature babies are smaller and weaker. This means they may have difficulty with blood and oxygen circulation, digestion and fighting infection. This increases their chances of developing NEC.
  • High-risk babies, especially premature babies, who are fed milk by mouth or tube feedings are more likely to get NEC. Babies who are fed breast milk are less likely to get NEC. It is rare in babies who haven’t started feeding yet.
  • Babies who have gone through a difficult delivery or had low oxygen levels at birth are more likely to get NEC. When there is too little oxygen, the body sends the most blood and oxygen to the brain and heart first, reducing blood flow to the intestinal tract. This can cause less oxygen in blood reaching the colon.
  • Babies with too many red blood cells in the circulation are at an increased risk of developing NEC.
  • Babies with infections in the intestine are also more likely to get NEC.

Why is necrotizing enterocolitis a concern?

Damage to the intestinal tissues can cause a hole to form in the intestines. This lets the bacteria living inside the intestinal tract to leak out into the abdominal cavity and cause infection. The damage may only exist in a small area or it may expand to large areas of the intestine. This can happen very quickly. An infection in the intestines is hard for a baby to fight. Even with treatment, there may be serious problems. Some of these problems are:

  • A hole forming in the intestine
  • Scars or strictures (narrow areas) forming in the intestine
  • Failure to use food and nutrients. This can happen if large amounts of intestine must be removed, leading to short bowel syndrome.
  • Severe, overwhelming infection.

What are the symptoms of necrotizing enterocolitis?

Each child may experience symptoms differently. Symptoms usually show up in the first two weeks and may include:

  • Bloating or swelling of the belly (abdominal distention)
  • Food doesn’t move through to the intestines as normal
  • Greenish-colored fluid (bile) in the stomach
  • Bloody bowel movements
  • Signs of infection, including:
    — Breathing that stops and starts (apnea)
    — Low heart rate
    — Sluggishness (lethargy).

The symptoms of necrotizing enterocolitis may be the same as other digestive conditions or medical problems. Always see your baby’s health care provider for a diagnosis.

How is necrotizing enterocolitis diagnosed?

Your baby’s health care provider will check him or her for signs of NEC. An X-ray of the abdomen may be recommended. The X-ray can show if the intestine has a bubbly appearance or if signs of air or gas are in the large veins of the liver. Air may also be outside the intestines in the abdomen. It may be necessary to put a needle into the abdominal cavity (belly) to see if intestinal fluid is in the abdomen. This is a sign of a hole in the intestines.

How is necrotizing enterocolitis treated?

Specific treatment for necrotizing enterocolitis will be determined by your baby’s health care provider based on:

  • The baby’s age
  • His or her overall health and medical history
  • How sick he or she is
  • How well your baby can handle specific medications, procedures or therapies
  • How long the condition is expected to last
  • Your opinion or preference.

Treatment may include:

  • Stopping feedings
  • Running a tube from the nose to the stomach (a nasogastric (NG) tube) to keep the stomach empty
  • Giving your baby intravenous fluids (IV) and nutrition through the vein (TPN)
  • Giving antibiotics for infection
  • Taking several X-rays to check the progress of the disease
  • Giving extra oxygen or using mechanically assisted breathing if the abdomen is so swollen that it interferes with breathing
  • Isolating your baby (using protective gowns and gloves) to keep any infection from spreading.

Severe cases of NEC may require:

  • Surgery to remove diseased intestine or bowel
  • Connecting part of the intestine or bowel to an ostomy (opening on the abdomen)
  • Draining the abdominal (peritoneal) cavity.

Can necrotizing enterocolitis be prevented?

Because the exact causes of NEC are unclear, it is often difficult to prevent it. Studies have found that babies who have had only breast milk (rather than formula) are less likely to develop NEC. Also, starting feedings after a baby is stable and slowly increasing feeding amounts have been recommended.